The present invention relates to a collision safety device at an end section of a crash barrier and comprising at least one crash barrier girder or profile extending a distance above and approximately along the ground, a safety member in the area of the end portion of the crash barrier, the safety member being disposed to be hit by a colliding vehicle, and, under the action thereof, to be displaced along the crash barrier, the safety member having a forming device engaging with the crash barrier girder for realising an energy-absorbing configurational change in the crash barrier girder on the displacement of the safety member along the crash barrier.
The present invention also relates to a method of preventing or reducing damage to a vehicle and injuries to its passengers if the vehicle collides with an end section of a crash barrier, and comprises the steps that a crash barrier girder or profile included in the crash barrier is provided with a forming device, which, under the action of the colliding vehicle, is displaced along the crash barrier, the crash barrier girder being reshaped or bent while absorbing energy from the colliding vehicle.
Crash barriers occur in a multiplicity of different variations and are used to restrain a vehicle which, for some reason, has deviated from its course. The crash barriers consist of a barrier girder or profile which is supported by posts extending roughly parallel along the ground and a slight distance above it. There are variations in which several barrier girders or profiles are employed superposed over one another, but also variations in which a single narrow and tall profile is employed. Variations in which taut wire rope is employed instead of crash barrier girders or profiles also occur.
Regardless of how the crash barrier is constructed, the end of a crash barrier is a critical area, since it may constitute an accident hazard in the event of a vehicle colliding with the end of the barrier. There are various solutions in existence as regards eliminating these risk factors as far as is possible.
A common variation entails that a single and relatively tall crash barrier profile gradually tapers towards the ground in order to terminate below ground level. Such a termination of a crash barrier entails that the vehicle avoids being stopped dead, but instead the vehicle is gradually lifted up by the crash barrier termination as the vehicle rides along it. An overturning vehicle may easily be the result. In addition, the installation of such a termination section to a crash barrier requires extensive excavation work
There are also variations in which a protection member or impact retardation member is placed at the end of a crash barrier facing towards the traffic, the crash barrier having a tall, narrow upright barrier profile which is approximately W-shaped in cross section, the protection member or retardation member having a considerably larger surface area facing towards a colliding vehicle than the cross-sectional area of the barrier profile included in the crash barrier, the protection or retardation member being intended to be hit by a colliding vehicle. The posts which, most proximal the retardation member, support the crash barrier profile are manufactured of wood and have lines of weakness so that they give way in a controlled manner in the event of a collision against the crash barrier. The retardation member is disposed at the end of an assembly which faces towards the traffic and which, on collision, is intended to be displaced along the crash barrier profile. This assembly includes a reforming device which, on displacement of the assembly along the crash barrier profile, first flattens out the profile so that this assumes a form which at least approximates the form of a sheet metal strip standing on end. The reforming device further includes a bending device which, after flattening of the profile horizontally, bends out the flattened profile in the lateral direction when the assembly with the retardation member is displaced along the crash barrier.
In certain cases, the above-described constructions may function well, but cannot be employed between closely adjacent traffic lanes, since the flattened profile is projected out laterally into one of the traffic lanes, where, naturally, it constitutes a dangerous obstacle.
The prior art constructions further suffer from drawbacks in the form of complicated and expensive assembly (with extensive excavation work), and other accident hazard risks, etc.
The present invention has for its object to design the collision safety device and the method of preventing or reducing damage to a vehicle and injuries to its passengers disclosed by way of introduction such that the drawbacks inherent in prior art technology are thereby obviated. In particular, the present invention has for its object to design the collision safety device in such a manner that it will be simple and economical to assemble and, as far as possible, eliminates accident risks and provides a gentle deceleration of a colliding vehicle. Finally, the present invention has for its object to design the collision safety device in such a manner that it may also be employed between closely adjacent traffic lanes with complete protective effect.
The objects forming the basis of the present invention will be attained in respect of the collision safety device if this is characterized in that the forming device has an entry end in line with the undeformed crash barrier girder and an exit end at a lower level in order that the deformed crash barrier girder can be driven over by the colliding vehicle.
In one preferred embodiment of the collision safety device according to the present invention, it also suitably applies that the free end of the crash barrier girder is connected to a tension or drawing device such a wire rope, chain or drawbar, the drawing device extending substantially in the longitudinal direction of the crash barrier to the side of the safety member facing away from the crash barrier where it is anchored in an anchorage device secured in the ground.
The objects forming the basis of the present invention will be attained in respect of the method if this is characterized in that the crash barrier girder is curved obliquely downwards towards the ground, that it is placed at a height level to be able to be driven over by the colliding vehicle, and that its longitudinal direction is kept substantially unchanged compared with the original longitudinal direction of the crash barrier.